Study busts conventional wisdom on price and reliability.

You've probably heard the argument: wind and solar power are well and good, but what about when the wind doesn't blow and the sun doesn't shine? But it's always windy and sunny somewhere. Given a sufficient distribution of energy resources and a large enough network of electrically conducting tubes, plus a bit of storage, these problems can be overcome—technologically, at least.

But is it cost-effective to do so? A new study from the University of Delaware finds that renewable energy sources can, with the help of storage, power a large regional grid for up to 99.9 percent of the time using current technology. By 2030, the cost of doing so will hit parity with current methods. Further, if you can live with renewables meeting your energy needs for only 90 percent of the time, the economics become positively compelling.

"These results break the conventional wisdom that renewable energy is too unreliable and expensive," said study co-author Willett Kempton, a professor at the University of Delaware's School of Marine Science and Policy. "The key is to get the right combination of electricity sources and storage—which we did by an exhaustive search—and to calculate costs correctly."

By exhaustive, Kempton is referring to the 28 billion combinations of inland and offshore wind and photovoltaic solar sources combined with centralized hydrogen, centralized batteries, and grid-integrated vehicles analyzed in the study. The researchers deliberately overlooked constant renewable sources of energy such as geothermal and hydro power on the grounds that they are less widely available geographically.

These technologies were applied to a real-world test case: that of the PJM Interconnection regional grid, which covers parts of states from New Jersey to Indiana, and south to North Carolina. The model used hourly consumption data from the years 1999 to 2002; during that time, the grid had a generational capacity of 72GW catering to an average demand of 31.5GW. Taking in 13 states, either whole or in part, the PJM Interconnection constitutes one fifth of the USA's grid. "Large" is no overstatement, even before considering more recent expansions that don't apply to the dataset used.

The researchers constructed a computer model using standard solar and wind analysis tools. They then fed in hourly weather data from the region for the whole four-year period—35,040 hours worth. The goal was to find the minimum cost at which the energy demand could be met entirely by renewables for a given proportion of the time, based on the following game plan:

When there's enough renewable energy direct from source to meet demand, use it. Store any surplus.

When there is not enough renewable energy direct from source, meet the shortfall with the stored energy.

When there is not enough renewable energy direct from source, and the stored energy reserves are insufficient to bridge the shortfall, top up the remaining few percent of the demand with fossil fuels.

Perhaps unsurprisingly, the precise mix required depends upon exactly how much time you want renewables to meet the full load. Much more surprising is the amount of excess renewable infrastructure the model proposes as the most economic. To achieve a 90-percent target, the renewable infrastructure should be capable of generating 180 percent of the load. To meet demand 99.9 percent of the time, that rises to 290 percent.

"So much excess generation of renewables is a new idea, but it is not problematic or inefficient, any more than it is problematic to build a thermal power plant requiring fuel input at 250 percent of the electrical output, as we do today," the study argues.

Increasing diversity, reduced need for back-ups

The jump from 90 to 99.9 percent provision does require greater diversity in the renewable sources used, requiring "significant amounts" of inland wind, offshore wind, and photovoltaic solar power. However, that greater diversity actually reduces the need for both energy storage and fossil fuel back-ups compared with 90-percent provision because the chances of usable energy coming from somewhere are greater. To meet the demand only 30 percent of the time, inland wind alone is sufficient, the study finds.

Efficiencies improve further if, rather than being stored, surplus energy is used to offset gas to provide heating. This is viable, the argument goes, despite the inferior efficiency of electric heating because the costs of renewable energy is largely capital. Once built, the cost of "fuel" is effectively zero, unlike gas. It's cheaper to use it than store it, the researchers argue, even if you use it relatively inefficiently.

But this is all moot if renewables can't compete with fossil fuels. The key to finding out whether they can is the researcher's estimate that the total cost today of providing 1kWh of electricity via the PJM Interconnection is 17¢. The researchers used 2008 costs to calculate what it would take to supply all power from renewables for 30 percent of the day. By the researcher's calculations, the cost is already cheaper than the figure, coming in at 10 ¢/kWh.

However, for 90 percent, the cost jumps to to 19 ¢/kWh best case (which uses hydrogen storage), while the cost for 99.9 percent coverage rises to a best case (using vehicle storage) of 26 ¢/kWh. These rates include the cost of procuring and installing the energy infrastructure in the first place.

Wormhole your way to 2030, however, and it's a different story. A target of 90 percent coverage falls to to 9¢/kWh (vehicle storage) or 10 ¢/kWh (hydrogen storage), while a 99.9-percent target falls to 17 ¢/kWh for either vehicle or hydrogen storage. Central battery storage is more expensive, at 15 or 25 ¢/kWh for 90 or 99.9-percent coverage. And, according to the research, you can knock a few cents of all of these figures if you use energy surpluses to offset gas for heating. Then, the cost of meeting 90-percent coverage using vehicle storage comes in at 6 ¢/kWh at 2030 tech prices, for example. Costs are adjusted to 2010 dollar-value for ease.

"Aiming for 90 percent or more renewable energy in 2030, in order to achieve climate change targets of 80-90 percent reduction of CO2 from the power sector, leads to economic savings, not costs," the researchers find. They suggest the sensible approach is to strive for a minimum target of 30 percent now, rising to 90 percent by 2030. Remember, that's not meeting 30 percent of your energy demand with renewables—it's meeting 100 percent of the demand with renewables for 30 percent of the time.

Because the renewables will inevitably contribute at other times, this amounts to about 60 percent of energy demand, the researchers claim. However, they argue that that subsidies for renewable energy, nuclear power and fossil fuels, ignored in the study's cost calculations, provide a barrier to the market finding the least costly technology mix.

It's worth remembering that the findings apply to a very specific case: the PJM Interconnection. How transferable and how scalable—down as well as up—the lessons are is open to discussion. And the research does weigh projected technology costs against current fossil fuel costs, so we are firmly inside the realm of the hypothetical. However, the researchers argue that by using energy surpluses to offset gas for heating rather than selling it to other markets, they are actually under-valuing it. It's also worth noting than one author declared an interest in a solar education startup, another in an grid-integrated vehicle startup.

Ultimately, the researchers are effectively proposing a brand new paradigm for energy provision. Today, fossil fuels are consumed at a rate conversant with hourly demand. More recent emerging wisdom, tied in with the "smarting" of the grid, holds that for renewable energy to be viable, non-essential loads must be shed (i.e. turned off) at times of peak demand. So, having provided enough renewable energy to meet minimum demand, additional needs are met with fossil fuels, while non-essential demands are delayed or denied. A modern washing machine might delay its spin cycle, a warehouse might turn off its AC for a while (and perhaps get energy discounts for doing so). But this approach is flatly dismissed in this research.

"If we applied the findings of this article, in the future we would build variable generation, designing for enough capacity to make electric load for the worst hours, and as a side effect we will have enough extra electricity to meet thermal loads," the study concludes.

156 Reader Comments

Good luck. Just remember there are no free lunches. An assumption that renewables have no negative effects would be wrong. Massive solar and wind will certainly also affect weather patterns. Also there may be net torques applied to the earth's rotation. Continue to pursue but don't be blinded by your cause.

If you wait for the fossil energy crunch, then it gets more expensive and difficult to actually transition to an alternative structure.

Not necessarily. Prematurely investing in an infrastructure that ends up being superseded can be very costly as well, meaning the best option is sometimes to wait as long as possible before committing. Not saying that's definitely the case here, but it's possible.

I think the biggest problem with this entire issue is that they are still thinking in terms of "the grid". It's this centralized monolithic power generating system. When you do it that way, it's going to be highly inefficient. The proper solution is a de-centralized system where power is generated in the locality where it is used. Spread the system out to the areas the energy is intended to be used. Solar cells and wind power on every building. There's even technology on the way that can turn a window into a source of energy by applying a film to the glass that converts sunlight to energy. That would make those big glass office buildings in metro areas huge power generators.

The basic point is, that renewable energy will never work when used in a conventional centralized grid system. We have to think about de-centralized models that fit the needs of the local area instead of pumping out huge amounts of energy whether it gets used or not.

The grid is only inefficient because it is not monolithic; it is transmitting power in a way that is too distance-limited to stabilize the inherently unstable renewable power sources. And while homes and small offices might be just fine with the prospect of power cuts based on otherwise-benign local weather, large-scale industrial and commercial users will just burn more fossil fuels less efficiently using the standby generators they likely already have. The grid needs to be improved, certainly, but abolishing it only abolishes the idea of stable electricity.

If you wait for the fossil energy crunch, then it gets more expensive and difficult to actually transition to an alternative structure.

Not necessarily. Prematurely investing in an infrastructure that ends up being superseded can be very costly as well, meaning the best option is sometimes to wait as long as possible before committing. Not saying that's definitely the case here, but it's possible.

indeed - that's why it's called the "bleeding edge". if you wait a while after a given tech comes out, whether it's video cards, cars, TVs, windmills, or whatever, the same or equivalent tech (if it survives/succeeds - remember automatic seatbelts?) gets cheaper, smaller, and better as time goes on. so no matter what field it's in, there's the "early adopter tax" to deal with.

I think the biggest problem with this entire issue is that they are still thinking in terms of "the grid". It's this centralized monolithic power generating system. When you do it that way, it's going to be highly inefficient. The proper solution is a de-centralized system where power is generated in the locality where it is used. Spread the system out to the areas the energy is intended to be used. Solar cells and wind power on every building. There's even technology on the way that can turn a window into a source of energy by applying a film to the glass that converts sunlight to energy. That would make those big glass office buildings in metro areas huge power generators.

The basic point is, that renewable energy will never work when used in a conventional centralized grid system. We have to think about de-centralized models that fit the needs of the local area instead of pumping out huge amounts of energy whether it gets used or not.

Energy systems MUST use a grid. It's the only way to ensure power availability 100% of the time, or, in the event that it's not possible, it's also the only way to manage outages.

The grid is only inefficient because it is not monolithic; it is transmitting power in a way that is too distance-limited to stabilize the inherently unstable renewable power sources. And while homes and small offices might be just fine with the prospect of power cuts based on otherwise-benign local weather, large-scale industrial and commercial users will just burn more fossil fuels less efficiently using the standby generators they likely already have. The grid needs to be improved, certainly, but abolishing it only abolishes the idea of stable electricity.

my thoughts on "the grid" was that by design it's DE-centralized, on purpose, to provide redundancy and distribute the load. that makes things more reliable and makes users less dependant on a single source of energy.

Transmission losses limit long distance power distribution to a few hundred miles/km. Super conducting lines becoming cheaper might make doing so feasible in the future; but you'd have an enormous capital expenditure to expand the grid first.

One estimate I saw was that it would take a mile wide belt of new lines IIRC 52 total (17? (feet vs yards)) to carry enough wind power from Nebraska to Illinois to power the city of Chicago. For scale Nebraska is roughly the size of England; Iowa is about 2/3rds as wide. The cost for building the lines themselves was more than that of building the wind turbines (and that estimate ignored the cost of acquiring the land to build them on) or the size of the US bailout at the start of the recession. Powering an entire country instead of just one large city would cost tens of trillions or more.

Edit: It might still be cheaper than building out the equivalent solar capacity in the cloudy north; but it will be a staggeringly expensive long term project.

That's funny, because the researchers in this very article contradict you. Did you even read it?

Aside from the abstract and tables the article is behind a paywall so I can't see what assumptions the authors did or didn't consider. I know a number of other optimistic studies only looked at the cost of building enough generating capacity where it could be done the cheapest; but ignored the much larger cost of massively expanding the transmission network to handle the much larger average distance between producers and consumers.

Edit: The reason we'd need to build out large amounts of additional transmission lines is that most of the power on the grid is consumed near where it's produced. The main exceptions are around large hydro power installations in the middle of nowhere. Otherwise current long distance transmission line capacity is only sufficient to keep things running when demand spikes and temporary local plant shutdowns result in small local shortages. Shifting one or two large plants worth of spare power requires much less than shifting the equivalent of 10 or 30 large plants worth that you'd need to handle a single large state being becalmed. The midatlantic region (VA, MD, PA, WV, NJ, DE) has ~80 large fossil fuel plants (>300MW) and 8 nuclear plants (size not specified; but they tend to be around 1 GW).

Can one of ars authors do us a favor and post a sensible enviro article? Currently wind power is 2% of energy budget, and increasing its share even to measly 20% would require 1000000 wind turbines covering the entire area of the state of Idaho. It is more likely that a single ITER would deliver more energy to the grid than the entire renewable industry.

Did I miss the part where they say how the energy would be stored? I've seen a few articles on that over the years at ars but only the experimental stage. It sounds like they're proposing either storing as hydrogen* (which would require a whole bunch of new plants) or in electric car batteries in people's houses (but what would that do to the lifespan of said batteries, and how do we retrieve it when the cars are all driving to work.)

Decent study, but would require a whole lot of infrastructure changes.

One of the storage medium solutions I find most interesting is the concept of the 'smart grid', where electricity is sent to where it is required and kept moving rather than wasted. A 'smart' national grid with local storage as well could be a solution.

A study I read a year or two ago found that in some areas the increased coal being burned due to the efficiency losses was large enough that total coal user would be lower if the wind turbines were shut down and the coal plants ran at a higher but more stable level.

If that were true, they could just burn it at the higher but more stable level regardless of wind anyway.

Studies in Britain have shown consumption is more variable and varies more rapidly than wind ("commercial breaks in Downton Abbey can lead to sudden demand spikes of hundreds of megawatts in just a few seconds"). Besides, with wind you can forecast production a day in advance with reasonable accuracy.

I think the biggest problem with this entire issue is that they are still thinking in terms of "the grid". It's this centralized monolithic power generating system. When you do it that way, it's going to be highly inefficient. The proper solution is a de-centralized system where power is generated in the locality where it is used. Spread the system out to the areas the energy is intended to be used. Solar cells and wind power on every building. There's even technology on the way that can turn a window into a source of energy by applying a film to the glass that converts sunlight to energy. That would make those big glass office buildings in metro areas huge power generators.

The basic point is, that renewable energy will never work when used in a conventional centralized grid system. We have to think about de-centralized models that fit the needs of the local area instead of pumping out huge amounts of energy whether it gets used or not.

I'm not sure why people are voting this down. Maybe they're not aware of transmission losses.

Can one of ars authors do us a favor and post a sensible enviro article? Currently wind power is 2% of energy budget, and increasing its share even to measly 20% would require 1000000 wind turbines covering the entire area of the state of Idaho. It is more likely that a single ITER would deliver more energy to the grid than the entire renewable industry.

How is electrical heating less efficient than "gas" heating (by "gas" I assume you mean natural gas)?

electrical heat has two main downfalls i can think of right off the top of my head: generation efficiency and transmission loss.

natural gas nas neither of those downfalls, and modern heaters have gotten efficiencies up into the 90% range. since there is no transmission loss with gas, and "generation" costs are nowhere near what electrical's are (gas treatment (to put in the mercaptan "smell") and storage/pumping facilities are not as complex as power generation stations. In fact, some of them are completely self-sufficient - they burn some of the gas to power the compressor engines, and generate enough power to run the plant itself. this is why natural gas is usually still functional after a natural disaster like an ice storm or hurricane.

the other big plus for gas heat is that the actual heat generation happens right where it's needed. in a gas-fired electrical plant, you use gas to boil water, which turns turbines, then pushes that power down the lines to the end user. there's no way that can possibly be as efficient as simply burning the gas right on site to achieve the same result (warm air), because there's more moving parts in between to reduce efficiency.

I was wondering about that. Cars are subsidized to run on electricity instead of gas, while in the house we are advised to use gas instead of electricity. What's the rationale here?

I was wondering about that. Cars are subsidized to run on electricity instead of gas, while in the house we are advised to use gas instead of electricity. What's the rationale here?

first, don't confuse the two different fuels (though some vehicles can run on CNG).

burning natural gas for heat is much more efficient than burning gasoline (which has a higher up-front "cost" than natural gas due to refineries and distribution) to move cars/trucks/etc. but i don't know how the total supply chain efficiency of an electric car compares to a gasoline car.

however, there's no doubt that when a car isn't moving (such as sitting in traffic, at a red light, or waiting at the curb to pick up a passenger) the electric one pollutes (even indirectly) infinitely less than the gasoline one. that's why some auto manufacturers (including subaru) have started to build automatic start/stop tech into their gasoline-powered cars, and that's the biggest selling point of an electric car.

Not that I would expect it to, but I'm sure it doesn't take into account the effects of government lobbying by oil and natural gas. I suspect they will completely bury this, if not discredit it. Along with setting up massive tax incentives/subsidies that favor the use of fossil fuels, thus making it cost ineffective to use something else.

I was wondering about that. Cars are subsidized to run on electricity instead of gas, while in the house we are advised to use gas instead of electricity. What's the rationale here?

Different uses, the logic goes that if you are heating your home with electric heat which is more or less a 100% conversion, the processing and delivery of the energy from a power plant (for ease we'll say a natural gas power plant) actually equates to being 60%. If that natural gas is delivered straight to you your furnace is burning it directly at the source and this is more efficient than having the power plant convert to energy delivered then used by you.

I was wondering about that. Cars are subsidized to run on electricity instead of gas, while in the house we are advised to use gas instead of electricity. What's the rationale here?

Different uses, the logic goes that if you are heating your home with electric heat which is more or less a 100% conversion, the processing and delivery of the energy from a power plant (for ease we'll say a natural gas power plant) actually equates to being 60%. If that natural gas is delivered straight to you your furnace is burning it directly at the source and this is more efficient than having the power plant convert to energy delivered then used by you.

The study purposefully excludes hydroelectric generation, which is one resource the British Isles potentially have more of than nearly every other country. But this assumes that Great Britain wouldn't include itself in an EU-wide electric grid, which seems rather silly when you consider the potential cost benefit over the longterm. Particularly as EU countries best suited for power production are also amongst the least wealthy and economically healthy. This could be a way for the EU to kill two birds with one stone, really.

I would love to see an EU wide grid that brought solar electricity from southern Europe to the wealthier north. It could help to hold the union together economically whilst dramatically cutting carbon emissions. Since Germany had decided to dump nuclear completely (based mostly on irrational, but emotive arguments) energy demands have become that little bit more urgent.

As a side note, even if there were a real basis to German safety concerns over nuclear power they have not fixed the problem - they are replacing their own nuclear production with nuclear electric imported from just over the French border instead. Fallout doesn't respect national borders.

I think Germany did this so that they would become leaders in wind power, which will give them many jobs over then next few decades. Manufacturing these takes massive machines and getting them there and the bugs worked out will pay dividends in job production.

They might back down on Nuclear as the last generators need to go offline in a decade or so. But for the old designs it is probably a good thing.

Not that I would expect it to, but I'm sure it doesn't take into account the effects of government lobbying by oil and natural gas. I suspect they will completely bury this, if not discredit it. Along with setting up massive tax incentives/subsidies that favor the use of fossil fuels, thus making it cost ineffective to use something else.

They've been less than successful at doing that recently. Wind has a significant subsidy in the form of grid operators being forced to buy at whatever cost the wind companies need to cover their costs; this has resulted in a large fraction (a majority?) of the new power being added to the grid in the last decade or so being wind base. From the other direction, after roughly a decade of fighting in the courts coal's taking a major hit in the form of old plants losing their grandfathered exemption to the clean air act and needing very expensive upgrades (locally one plant that's being refit is spending somewhere between $100m and $150m for each of 3 ~250MW generation units being upgraded). A large number of the oldest coal plants in the nation are being scrapped as a result with a combination of wind and natural gas taking their place. NG's not perfect but it's roughly half as carbon intensive as coal, and even when things go wrong fracking is nowhere near as disruptive as mountaintop removal mining; in any event we don't have the production capacity to build wind generation fast enough to replace all the old coal plants before they're forced offline.

A study I read a year or two ago found that in some areas the increased coal being burned due to the efficiency losses was large enough that total coal user would be lower if the wind turbines were shut down and the coal plants ran at a higher but more stable level.

If that were true, they could just burn it at the higher but more stable level regardless of wind anyway.

Studies in Britain have shown consumption is more variable and varies more rapidly than wind ("commercial breaks in Downton Abbey can lead to sudden demand spikes of hundreds of megawatts in just a few seconds"). Besides, with wind you can forecast production a day in advance with reasonable accuracy.

Ars has a lot of really smart people from diverse backgrounds so why don't we do some brainstorming? To start off, here are my off-the-cuff ideas. They're quite probably completely impractical -- particularly from the political standpoint -- but they're a starting point:

GridCreate a superconducting backbone grid for Canada and the US comprising 2 north-south lines and one east-west line. The western north-south line goes between the coastal mountains and the Rockies and extends from northern British Columbia to the California-Arizona border. This keeps it relatively close to major cities and major hydro facilities but away from major seismic zones. The eastern north-south line is much less geographically constrained so it would be routed to optimize the distance from population centres while connecting to the hydro facilities in New York, Ontario, and Quebec. The east-west line connects the north-south lines together and would be routed to optimize the distance from population centres and areas suitable for wind and/or solar generation. Sorry Mexico, you really don't bring anything to the table so you're on your own.

StorageGo vertical? We've got these tunnel borer critters that seem to do a great job of making fairly wide holes (10 metres?) so let's point them down and start digging. Once we've got a hole that's deep enough (whatever that is) we put in a generating station at the halfway point and a pumping station at the bottom. Fill the top section with water and away we go.

Finally someone agrees with me, and with data to back it up! But the only thing I disagree with is the time to cost parity. 2030? I'd be my livelihood on 2020. The rabid pace of battery and solar development seems to only be growing, and lithium air batteries that don't degrade over time along with 30+ percent efficiency solar panels are quite the possibility within 7-8 years

I think the biggest problem with this entire issue is that they are still thinking in terms of "the grid". It's this centralized monolithic power generating system. When you do it that way, it's going to be highly inefficient. The proper solution is a de-centralized system where power is generated in the locality where it is used. Spread the system out to the areas the energy is intended to be used. Solar cells and wind power on every building. There's even technology on the way that can turn a window into a source of energy by applying a film to the glass that converts sunlight to energy. That would make those big glass office buildings in metro areas huge power generators.

The basic point is, that renewable energy will never work when used in a conventional centralized grid system. We have to think about de-centralized models that fit the needs of the local area instead of pumping out huge amounts of energy whether it gets used or not.

I'm not sure why people are voting this down. Maybe they're not aware of transmission losses.

Electricity will naturally take the path of least resistance. I expect energy you generate to go to your neighbors before it decides to take a cross-country hike.

Unless there is something really weird with transformers, AC should be able to leave a house as easily as it enters.

So a 40% inefficiency, which would also hold for electric cars. How does that compare to cars on natural gas (they do exist, but I don't know their efficiency).

Of course once cars are converted to electricity, they will get greener when the grid gets greener. So long term, I see the value.

For cars the differences become more pronounced because you're using them both to run a motor, with home heating you're burning the gas directly. Electrics are good at motors. An electric engine is way more efficient than a combustion engine. The biggest problem with electric vehicles is energy density and batteries.

I wonder if the $40 paywall is symbolic of how much money this proposed new storage and generation system would cost. I'm especially interested in how they plan to store all that excess energy and how much they expect the infrastructure to cost. Every estimate I've ever seen has a whole lot of zeroes in it.

One issue I'm also curious about is how fossil fuel backup generation will work. If the plan is to have the gas plants only turn on when there is not enough power from generation or storage to meet demand, it doesn't sound like they'll be operating very much. That is to say, they don't sound profitable. And if they're not going to be profitable, who is going to build them?

So a 40% inefficiency, which would also hold for electric cars. How does that compare to cars on natural gas (they do exist, but I don't know their efficiency).

Why would that also hold for electric cars? Electric cars are not trying to generate heat. They are trying to convert the electricity into motion, which is a completely different process. And actually, electric car engines have extremely high efficiencies (in the order of 80% I believe...final efficiency isn't as high due to transmission, generation, and charging losses, but still significantly higher than ICE).

Not sure about natural gas engines, but I assume they use some sort of ICE design, which are ridiculously inefficient (around 20%).

I was wondering about that. Cars are subsidized to run on electricity instead of gas, while in the house we are advised to use gas instead of electricity. What's the rationale here?

Different uses, the logic goes that if you are heating your home with electric heat which is more or less a 100% conversion, the processing and delivery of the energy from a power plant (for ease we'll say a natural gas power plant) actually equates to being 60%. If that natural gas is delivered straight to you your furnace is burning it directly at the source and this is more efficient than having the power plant convert to energy delivered then used by you.

So a 40% inefficiency, which would also hold for electric cars. How does that compare to cars on natural gas (they do exist, but I don't know their efficiency).

Of course once cars are converted to electricity, they will get greener when the grid gets greener. So long term, I see the value.

For cars the differences become more pronounced because you're using them both to run a motor, with home heating you're burning the gas directly. Electrics are good at motors. An electric engine is way more efficient than a combustion engine. The biggest problem with electric vehicles is energy density and batteries.

Exactly. If the DoE's new "Manhattan Project" to develop batteries with 5 times electric density, 5 times cheaper, in 5 years works out (huge IF) then every car built after the technology is commercialized will be electric. There just is no way that ICE technologies, will come close to competing with that.

Ars has a lot of really smart people from diverse backgrounds so why don't we do some brainstorming? To start off, here are my off-the-cuff ideas. They're quite probably completely impractical -- particularly from the political standpoint -- but they're a starting point:

GridCreate a superconducting backbone grid for Canada and the US comprising 2 north-south lines and one east-west line. The western north-south line goes between the coastal mountains and the Rockies and extends from northern British Columbia to the California-Arizona border. This keeps it relatively close to major cities and major hydro facilities but away from major seismic zones. The eastern north-south line is much less geographically constrained so it would be routed to optimize the distance from population centres while connecting to the hydro facilities in New York, Ontario, and Quebec. The east-west line connects the north-south lines together and would be routed to optimize the distance from population centres and areas suitable for wind and/or solar generation. Sorry Mexico, you really don't bring anything to the table so you're on your own.

StorageGo vertical? We've got these tunnel borer critters that seem to do a great job of making fairly wide holes (10 metres?) so let's point them down and start digging. Once we've got a hole that's deep enough (whatever that is) we put in a generating station at the halfway point and a pumping station at the bottom. Fill the top section with water and away we go.

The superconducting grid is a complete non-starter with the currently avaialble high T superconductors. Everything with transition temperature above the boiling point of liquid nitrogen, which is critical from a cost standpoint, is in the cuprate family. These materials have low critical current densities (the max current density before resistance jumps up), are difficult to manufacture, are extremely brittle, and are susceptible to eddy currents that cause local heating and failure. They also contain large amounts of relatively difficult to separate, or hazardous elements. This is all BEFORE you consider problems with manufacturing the lines themselves and the capital costs for deployment. These costs are not even close to balanced by resistance losses in copper over any reasonable time frame . When the cuprate family was discovered in the mid 1980's, there was a massive amount of work surrounding these materials, but it all stopped after a few years because the problems listed above make them completely unsuitable for almost any real application. Without a major breakthrough in superconducting materials, the superconducting grid will remain a fantasy.

GridCreate a superconducting backbone grid for Canada and the US comprising 2 north-south lines and one east-west line. The western north-south line goes between the coastal mountains and the Rockies and extends from northern British Columbia to the California-Arizona border..

You, sir, are a genius, but you forgot to suggest anti-matter power plants and transporter/replicator technology to speed transportation and to feed the hungry.

I'm told the way (at least the British) system works is sources are switched in or out of the grid based on demand, unit price and grid-transit losses at any given time and the storage capacity is essentially nill to a first approximation.

This leads to the madly inefficient situation where renewable (particularly wind) which were expensive to build but are producing energy for very low per-unit costs are often cut out of the system and the energy they could (or even are) producing is wasted while hydrocarbons are burned. The reason for this is because their owners are trying to recoup the large capital investment in the unit price they offer the grid making it higher at certain times than hydrocarbons.

Free markets are all very well, but the situation where you switch off a wind farm that is already built and producing energy with little cash or carbon overheads in favour of hydrocarbons is utterly daft. There must be sensible ways of addressing this. Maybe externalities pricing on the hydrocarbons might do it, or an obligation to use renewable at times when they could displace hydrocarbons, or simply smarter pricing systems that allow the renewable units to be priced competitively when they would otherwise be wasted but maintain the higher pricing at other times to cover upfront costs.

I don't know if its similar in the US?

Well, any business who's accounting system is set up this way is seriously outside the realm of standard cost accounting, that's all I can tell you. At no time is already spent capital cost a valid consideration in accounting in any way shape or form. Once you spend a dollar it is gone and the logic of accounting says it is just water under the bridge, walk on.

Of course that doesn't mean this isn't happening, but it is a POLITICAL problem, not an accounting problem. Different departmental organizations within the company, or different vendors, are acting in locally rational but globally disfunctional ways. While accounting for externalities might 'fix' the problem it is really a cost accounting issue at heart.

The up front expense of superconducting lines is large, but, over even as little as 30 years, and just a 200 mile run, the savings vs transmission losses compensate completely

Excuse me, are we writing Star Trek fan fiction or was there some huge technological breakthrough that I am unaware of?

If we are going to talk about super-conducting power lines, lets start talking about using Mr Fusion to generate power from banana peels.

Several short superconducting transmission lines are in operation. Maintaining the liquid nitrogen uses less energy than the resistive losses of an ordinary cable. Current installations are all small scale; but one designed for a 5GW load looks like it should be under construction either now or in the near future (The Tres Amiga's article isn't clear.)